Probable assignment of the Duffy blood group locus to chromosome 1 in man.

Abstract

In this paper (an abstract of which appeared earlier ') we report what we believe is the first assignment of a specific gene locus to a specific autosome in man.Estimates are given of recombination values between the common blood group/ serum protein loci and an element (Un) that controls the expression of an anom- alous uncoiled region of chromosome 1 in a newly studied family (V1lDE) as well as in two small pedigrees (V11CR and V11PP) reported in the literature.2 3 We present evidence that the Duffy blood group locus Fy, already believed to be linked to a congenital cataract locus4 Cae, is close to this uncoiler element Un, and that all three are probably on chromosome no. 1.A report of another family,5 slightly favoring linkage between Fy and one of the break points of a no. 1 inversion, is also considered.Methods.-Cytogenetic study: For chromosome analysis of family VllDE, venous blood was drawn with a heparinized syringe and cultured for 72 hr in a mixture of medium 199, fetal bovine serum, and phytohemagglutinin, according to a modification of the technique of Lejeune.6In this system, the lymphocytes underwent mitosis and were arrested at metaphase by 0.02 jg colchicine/ml culture fluid added for the final 2 hr of culture.At culture termination, the lymphocytes were treated with 0.9% (hypotonic) sodium citrate, fixed in 3: 1 ethanol-acetic acid and then placed on a slide, dried by flaming, and stained in a 4%/0 (v/v) giemsa solution.Polymorphic marker loci: Loci with two or more alleles were investigated in family VIlDE as follows.Blood group typing was done for antigens, A, B, D, C, c, E, e, M, N,